Abstract: A pressure discharge valve for storage tanks on land or trucks including a valve body having a through hole therein adapted to mate and communicate with a through hole in a wall of the storage tank, a first vent means comprised of a eutectic composition which automatically provides a partial release of storage tank liquid at a first predetermined temperature lower than critical combustion and/or explosive temperatures of liquid in the storage tank, to provide a visual signal and warning to firefighters of these hazardous conditions, and a second vent means comprised of a eutectic composition to automatically vent liquid in the storage tank through the hole in the valve body when the liquids therein reach a predetermined critical temperature. In addition, the pressure discharge valve preferably comprises a eutectic solder material disposed between the valve body and the second vent means, which changes phase (i.e.

Abstract: A pressure discharge valve for storage tanks on land or trucks including a valve body having a through hole therein adapted to mate and communicate with a through hole in a wall of the storage tank, a first vent means comprised of a eutectic composition which automatically provides a partial release of storage tank liquid at a first predetermined temperature lower than critical combustion and/or explosive temperatures of liquid in the storage tank, to provide a visual signal and warning to firefighters of these hazardous conditions, and a second vent means comprised of a eutectic composition to automatically vent liquid in the storage tank through the hole in the valve body when the liquids therein reach a predetermined critical temperature. In addition, the pressure discharge valve preferably comprises a eutectic solder material disposed between the valve body and the second vent means, which changes phase (i.e.

Abstract: A pressure discharge valve for storage tanks on land or trucks including a valve body having a through hole therein adapted to mate and communicate with a through hole in a wall of the storage tank, a first vent means comprised of a eutectic composition which automatically provides a partial release of storage tank liquid at a first predetermined temperature lower than critical combustion and/or explosive temperatures of liquid in the storage tank, to provide a visual signal and warning to firefighters of these hazardous conditions, and a second vent means comprised of a eutectic composition to automatically vent liquid in the storage tank through the hole in the valve body when the liquids therein reach a predetermined critical temperature. In addition, the pressure discharge valve preferably comprises a eutectic solder material disposed between the valve body and the second vent means, which changes phase (i.e.